1. Field of the Invention
The present invention relates to an apparatus for purging the ink jet head and an ink jet recorder including the ink jet head. In particular, the invention relates to an ink jet head purging apparatus which can suitably change the suction time interval depending on ambient temperature variations, and an ink jet recorder including the ink jet head.
2. Description of Related Art
A conventional ink jet printer includes a print head having a number of nozzles for ejecting ink to print a sheet of paper. While the head is used, air bubbles may be produced in it, and ink may stick to the nozzle walls, resulting in defective ejection of ink. If the printer is not used for a long time, the nozzles may clog with thick ink, resulting in defective ejection of ink. Defective ejection of ink results in defective print. In this case, the nozzles are purged to recover good ejection of ink. The purging includes capping the head with a suction cap, and sucking ink out of the capped head by a pump developing negative pressure. Normally, the nozzles are purged at regular interval of time, which may be five days.
Because the ink ejected from the print head is a viscous liquid, however, its state may change at abnormal temperature. Therefore, at abnormal temperature, if the nozzles are not purged frequently, the ejection of ink from nozzles may become defective. If the purging time interval is short on the assumption that the temperature may be abnormal, the purges at normal temperature are too frequent. This accelerates the ink consumption of the printer, because the purging involves suction of ink.